Method of shutting off water in oil wells



April 22 1924.

J. J. SMIT METHOD OF SHUTTING OFF WATER IN OL WELLS Filed Jan. l1. 1923 fn/mr Patented Apr. 22, 1924.

UNITED STATES l JAN J'. SMIT, O F LOS ANGELES, CALIFORNIA.

METHOD OF SHUTTING OFF WATER'IN OIL WELLS.

Application filed January 11, 1923. Serial No. 611,974.

To all rwhom it may concern Be it known that I, JAN J. SMIT, a subject of the Queen of the Netherlands, residing -at Los Angeles, in the county of Los Angeles and State of California, have invented new and useful Improvements in Methods of Shutting Off Water in Oil l/Vells, of which the following is a specification.

This invention relates to oil well drilling, and has for its object to provide a method for shutting ofi water in wells.

An object of the invention is to provide a method for sealing the well at diiferent levels at which water may be encountered for the obvious purpose of preventing' the down flow of the wat-er from the upper stratum to the oil intake when the well is on roduction.

ther objects and advantages will be made manifest in the following specification of an embodiment of the invention illustrated in the accompanying drawings, wherein- Figure l is a diagrammatic section indicating the initial plugging of the bottom of a well hole below a water stratum.

Fig. 2 shows the second step of introduc.- ing a mixture of cement and oil upon the bottom plug to a depth approximately equal to the water Stratum.

Fig. 3 isa diagrammatic section illustrating the lowering of a stem of casing into the well through the liquid cementitious seal and into engagement with the bottom plug.

Fig. 4 isa section showing the step of drilling through the bottom plug after the casing has been cemented in the water shut-oil'.

Fig. 5 is a sectional view showing a hell or skin surrounding the lower end of the casing.

According to the method of the present invention, a well hole 2 is run down in the usual manner until a water stratum W is encountered. As nearly as may be determined at the bottom of this stratum there is introduced into the well hole a. eementitious material to form a cement plug or block 3. After the cement block or plug has -set there is then introduced into the well a. cementitious mixture of oil and cement indicated a-t 4, Fig. 2. Such quantity of oilcement mixture 4 is introduced into the hole as will insure an effective water seal laround the contiguous port-ion of a string of casing, the lower end of which is shown at C, Fig. 3. The casingy end is advanced into the well and is preferably closed at its foot before it is entered into the well as by a cement choke 5 which may have an outer shoe'o-r protecting covering of metal 6. Beforev the water seal material 4 has set, the well string of casing C is lowered until the shoe engages the cement plugA 3 after which the well casing is permitted to rest on the plug until the sealing material 4 has thoroughly hardened and embeds the casing.

Following the cementing in of the casingv end, the choke 5 is drilled out as by a drilling tool D which asses then throuoh the plug 3, andthe dri ling of the hole 1s continued below the water stratum W that has been sealed ofl".

It is understood that this process may be repeated as often asis necesary in the original drilling of a. well or in the deepening of a well.

Itr may be desirable that the casing C should beremoved as for the deepening of the well, and to facilitate the pulling ofthe casing from the asphalt-like cement seat 4 the lower end of the casing C may be provided with a shell or skin S, for instance of sheet Steel having a length somewhat greater than the depth of the cement Seal 4, so that after this seal has set, instead of it gripping firmly upon the casing directly, it set-s upon the skin S and the casing can, therefore, be pulled from this skin while the latter is in the grip of the seal. This, therefore, provides for the ready deepening of the drill hole as of a diameter as large or larger than the diameter of the casing removed.

Further embodiments, modifications and variations may be resorted to within the spirit of the invention as here claimed.

Vhat is claimed is:

1. A method of shutting off water in deep wells which consists of forming a cement plug in a well below a water stratum to be shut oil from the well, introducing a water seal forming material above the said plug, lowering a casing into the well through the sealing material and permitting the sealing material to set around the casing, and there after drilling through the plug below the end of the casing.

2. A method of shutting oi water in deep Wells which consists f forming a cement plug in a Well below a water stratum to be shut off from the Well, introducing a Water and resting the casing on the plug and permitting the sealing material to set around the casing, and thereafter drilling through the plug below the end of the casing.

4. The method ofI deep well drilling wherein that portion of a string of casing which is immediately surrounded by a cernentitious shutting ofi' seal in the well, is provided with a shell or Skin so that the cement seal will set on the shell or skin thus permitting the pulling of the casing from the shell or skin While the latter is permanently embedded in the seal.

In testimony whereof I have signed my name to this specification.

JAN J. SMIT. 

